Non-volatile solid state data storage is an advancing technology for future data storage applications. Solid state data storage devices are typically better suited than disc drives for applications that require small form factors, low power consumption, and robust mechanical shock resistance. Among various silicon-based solid state data storage technologies, flash memory is non-volatile and offers very high storage densities. However, flash memory performance is limited by its long write times (about 0.1-1 microsecond) and a limited number of data overwrites that can be successfully achieved. One non-volatile solid state technology vying to compete with flash memory is magnetic random access memory (MRAM). Unlike flash memory, MRAM has infinite write endurance and orders of magnitude faster write times (about 1-10 nanoseconds). MRAM has a potential to achieve similar areal density and cost as flash memory when the magnetic bits are written in an MRAM cell via spin torque instead of with externally applied magnetic fields. However, there are unsolved problems with design margins and process variations in spin torque MRAM cells that limit the ability to make large MRAM arrays.
Aspects of the present invention provide solutions to these and other problems, and offer other advantages over the prior art.